Methods For Desolventization Of Bagasse

ABSTRACT

Provided herein are methods for the removal of organic solvents from wet bagasse. The use of the methods result in dried bagasse that contains no more than 1 weight percent organic solvents.

BACKGROUND

The Hevea plant or tree (also called Hevea brasiliensis or a rubbertree) is a well-known source of natural rubber (also calledpolyisoprene). Rubber sources such as Hevea brasiliensis, Ficus elastic(India rubber tree) and Cryptostegia grandiflora (Madagascar rubbervine)produce natural rubber in the form of a sap where the rubber issuspended in an aqueous solution that flows freely and can be recoveredby tapping of the plant. Various non-Hevea plants are also known tocontain natural rubber, but their rubber is stored within the individualcells of the plant (e.g., stems, roots or leaves) and cannot be accessedby tapping but can only be accessed by breaking down the cell walls byphysical or other means. Thus, processes for the removal of rubber fromnon-Hevea plants are generally more complicated and entailed thanprocesses for harvesting rubber from Hevea trees. The use of organicsolvent-based rubber extraction processes with non-Hevea plantsgenerally results in separate streams of rubber and bagasse. The bagassecontains a quantity of any organic solvents that are utilized in therubber extraction process.

SUMMARY

Part of the by-product of an organic solvent-based process for theremoval of rubber from non-Hevea plants is a quantity of wet bagasse orwet insoluble plant matter. The wet bagasse contains the material fromthe plant that has not solubilized in the organic solvents (i.e., mostlycellulose-type material along with some quantity of dirt) and residualorganic solvents from the rubber removal process. Disclosed herein areprocesses for removing organic solvents from wet bagasse.

In a first embodiment, a method for removing organic solvents from wetbagasse is provided. The method comprises utilizing a quantity of wetbagasse that contains up to 45 weight % combined organic solvents andwater (based upon the total weight of the wet bagasse) and no more than0.1 weight % rubber; heating the wet bagasse to a temperature of atleast 100° C. whereby the organic solvents are evaporated; and producingdried bagasse that contains no more than 1 weight % organic solvents.

DETAILED DESCRIPTION

Disclosed herein are processes for removing organic solvents from wetbagasse.

Definitions

The terminology as set forth herein is for description of theembodiments only and should not be construed as limiting the inventionas a whole.

As used herein, the term non-Hevea plant is intended to encompass plantsthat contain natural rubber within the individual cells of the plant.

As used herein the term “bagasse” is used to refer to that portion ofthe ground or chopped plant matter from a non-Hevea plant that isinsoluble and hence is suspended rather than dissolved by organicsolvents. As used herein, bagasse should be understood to include dirtand ash, unless otherwise specified.

As used herein the term “plant matter” means material obtained from anon-Hevea plant. Unless otherwise specified, the plant matter mayinclude roots, stems, bark, woody material, pith, leaves and dirt.

As used herein the term “resin” means the naturally occurring non-rubberchemical entities present in non-Hevea plant matter, including but notlimited to resins (such as terpenes), fatty acids, proteins, andinorganic materials.

As used herein the term “dirt” (such as used in the connection with thesolid purified rubber produced by the processes disclosed herein) meansnon-plant material that may be associated with non-Hevea plants,particularly upon harvesting, such as soil, sand, clay and small stones.Dirt content in solid purified rubber can be determined by completelyre-dissolving the solid rubber and pouring the solution through a 45micron sieve. The sieve is then rinsed with additional solvent anddried. The weight of the material retained on the sieve represents the“dirt” content of the solid purified rubber.

Processes

In a first embodiment, a method for removing organic solvents from wetbagasse is provided. The method comprises utilizing a quantity of wetbagasse that contains up to 45 weight % combined organic solvents andwater (based upon the total weight of the wet bagasse) and no more than0.1 weight % rubber; heating the wet bagasse to a temperature of atleast 100° C. whereby the organic solvents are evaporated; and producingdried bagasse that contains no more than 1 weight % organic solvents.

In a first sub-embodiment of the first embodiment, a method is providedfor removing organic solvents from wet guayule bagasse. The methodcomprises utilizing a quantity of wet guayule bagasse that contains upto 45 weight % combined organic solvents and water (based upon the totalweight of the wet bagasse) and no more than 0.1 weight % rubber. The wetguayule bagasse is heated to a temperature of greater than 100° C. byplacing the wet guayule bagasse in an apparatus containing multiplelayers, circulating heated air through the layers of the apparatus andpassing the wet guayule bagasse from one layer to another whereby theorganic solvents are evaporated. After evaporation of the organicsolvents, dried guayule bagasse that contains no more than 1 weight %organic solvents is produced.

In a second sub-embodiment of the first embodiment, a method is providedfor removing organic solvents from wet guayule bagasse. The methodcomprises utilizing a quantity of wet guayule bagasse that contains upto 45 weight % combined of acetone and hexane (based upon the totalweight of the wet guayule bagasse) and no more than 0.1 weight % rubber.The wet guayule bagasse is heated to a temperature of greater than 100°C. whereby the organic solvents are evaporated. After evaporation of theorganic solvents, dried guayule bagasse that contains no more than 1weight % organic solvents is produced.

The source of the bagasse may be one or more of various non-Hevearubber-containing plants. More specifically, the bagasse usually resultsfrom a rubber extraction process (e.g., organic solvent extraction) thatis performed upon a non-Hevea rubber-containing plant matter. It iscontemplated that various organic solvent-based processes may beutilized for extraction of the rubber from the non-Hevearubber-containing plant matter that produces the wet bagasse. Exemplaryorganic solvent-based processes are disclosed in U.S. Patent ApplicationSer. Nos. 61/607,448, 61/607,460 and 61/607,469, the entire disclosureof each being herein incorporated by reference.

In certain embodiments of the first embodiment (e.g., the first andsecond sub-embodiments described herein), the bagasse is from guayuleshrubs. More specifically, such bagasse usually results from a rubberextraction process that is performed upon guayule shrub plant matter.

As previously discussed, in the first embodiments and in the first andsecond sub-embodiments described herein, the wet bagasse or the wetguayule bagasse, respectively, contains up to 45 weight % combinedorganic solvents and water (based upon the total weight of the wetbagasse). The organic solvents comprise any organic solvents used toremove rubber and resins from the non-Hevea plant matter. The wetbagasse also may contain varying amounts of water and varying butgenerally very small amounts of unextracted rubber and unextractedresin. In certain embodiments according to the first embodiment and incertain embodiments of the first and second sub-embodiments of theprocesses disclosed herein, the wet bagasse contains up to 7-10 weight %water and up to 0.1 weight % unextracted rubber along with a certainamount of unextracted resin. Preferably, according to the firstembodiment and according to the first and second sub-embodiments of theprocesses disclosed herein, the wet bagasse contains no more than 8-10weight % organic solvents. Preferably, according to the first embodimentand according to the first and second sub-embodiments of the processesdisclosed herein, the wet bagasse contains no more than 0.05 weight %combined unextracted rubber.

As previously discussed, in the first embodiment and according to thefirst and second sub-embodiments, the wet bagasse or wet guayule bagasseis heated to a temperature of greater than 100° C. whereby the organicsolvents are evaporated. Depending upon the type of apparatus utilizedto heat the wet bagasse or wet guayule bagasse, it is possible thattemperatures somewhat lower than 100° C. can be utilized, such astemperatures from 70-100° C., as exemplified in the working Examples. Incertain embodiments according to the first embodiment and certainembodiments according to the first and second sub-embodiments, the wetbagasse or wet guayule bagasse is heated to a temperature between 110and 200° C. In certain other embodiments according to the firstembodiment and certain embodiments according to the first and secondsub-embodiments, the wet bagasse or wet guayule bagasse is heated to atemperature between 100 and 150° C. In yet other embodiments accordingto the first embodiment and certain embodiments according to the firstand second sub-embodiments, the wet bagasse or wet guayule bagasse isheated to a temperature between 125 and 150° C.

As those skilled in the art will appreciate the particular time duringwhich the heating of the wet bagasse or wet guayule bagasse is continuedcan be impacted by factors such as the quantity of wet bagasse, thecombined organic solvent and water content of the wet bagasse, thetemperature to which it is heated. In certain embodiments according tothe first embodiment and in certain embodiments according to the firstand second sub-embodiments of the processes disclosed herein, theheating of the wet bagasse (or wet guayule bagasse) occurs for 30 secondto 1.5 hours, including from 5 minutes to 90 minutes at a temperature of100-150° C. In certain embodiments according to the first embodiment andin certain embodiments according to the first and second sub-embodimentsof the processes disclosed herein, the heating occurs for no more than10 minutes at a temperature of at least 110° C. In other embodimentsaccording to the first embodiment and according to the first and secondsub-embodiments of the processes disclosed herein, the heating occursfor no more than 8 minutes at a temperature of at least 125° C.

As previously discussed, in the first embodiment and in the first andsecond sub-embodiments of the processes disclosed herein, the driedbagasse contains no more than 1 weight % organic solvent (based upon thetotal weight of the dried bagasse). In addition to the organic solventcontent of the dried bagasse, the dried bagasse may contain a quantityof water and higher boiling point terpenes. Generally, the totalquantity of water and higher boiling point terpenes in the dried bagassemay be higher than the content of organic solvents. Resin content(including the higher boiling point terpenes) in the dried bagasse isgenerally acceptable and in some instances actually preferred as theresin can be helpful in those embodiments where the dried bagasse isbriquetted or otherwise compressed. In certain embodiments of the firstembodiment of the processes disclosed herein, the dried bagasse containsno more than 0.5 weight % organic solvent (based upon the total weightof the dried bagasse).

As previously discussed, in the first embodiment and in the first andsecond sub-embodiments of the processes disclosed herein, the wetbagasse or wet guayule bagasse is heated to a temperature of at least100° C. whereby the organic solvents are evaporated. Various methods maybe utilized for the heating of the wet bagasse. In certain embodimentsaccording to the first embodiment, and according to the first and secondembodiments disclosed herein, the heating of the wet bagasse (or wetguayule bagasse) to the temperatures previously provided takes place inan apparatus selected from one of the following: i. a dryer containingmultiple layers, circulating heated air through the layers of theapparatus and passing the wet guayule bagasse from one layer to anotherwhereby the organic solvents are evaporated; ii. a dryer containingmultiple paddles for mixing the wet bagasse with heated air to evaporatethe organic solvent; or iii. a desolventization screw extruder. Incertain such embodiments, the heating is achieved by placing the wetbagasse (or wet guayule bagasse) in an apparatus containing multiplelayers, circulating heated air through the layers of the apparatus andpassing the wet bagasse from one layer to another. Suitable equipmentfor achieving such heating of the wet bagasse (or wet guayule bagasse)includes continuous tray-type dryers, including those with rotatingtrays and distributed trays such as those available from WyssmontCompany (Fort Lee, N.J.). In other embodiments, the heating is achievedby placing the wet bagasse (or wet guayule bagasse) in a dryercontaining multiple paddles for mixing the wet bagasse with heated airto evaporate the organic solvent. Suitable equipment for achieving suchheating of the wet bagasse (or wet guayule bagasse) includes continuoustype air swept tubular dryers, including those with paddles or bafflesfor mixing the wet bagasse with heated air, such as those available fromScott Equipment Co., New Prague, Minn. Further details as to exemplaryair swept tubular dryers are provided in U.S. Pat. No. 5,570,517, theentire disclosure of which is incorporated herein by reference. In yetother embodiments, the heating is achieved by placing the wet bagasse(or wet guayule bagasse) in a desolventization screw extruder. In otherembodiments, the heating is achieved by heated steam. Heating can alsobe achieved using a desolventizer, a dryer and/or a cooler.

In certain embodiments according to the first embodiment and accordingto the first and second sub-embodiments of the processes disclosedherein, the method of removing organic solvents from the wet bagassefurther comprises condensing the evaporated organic solvents andcollecting them separately from the dried bagasse.

According to the first sub-embodiment, a method is provided for removingorganic solvents from wet guayule bagasse. The method comprisesproviding a quantity of wet guayule bagasse that contains up to 45weight % combined organic solvents and water (based upon the totalweight of the wet guayule bagasse) and no more than 0.1 weight % rubber.(The organic solvents including any polar organic solvents and non-polarorganic solvents that may have been utilized in the rubber extractionprocess.) The wet guayule bagasse is heated to a temperature between 100and 200° C. by placing the wet guayule bagasse in an apparatuscontaining multiple layers, circulating heated air through the layers ofthe apparatus and passing the wet guayule bagasse from one layer toanother whereby the organic solvents are evaporated. After evaporationof the organic solvents, dried bagasse that contains no more than 1weight % organic solvents is produced.

In certain embodiments according to the first sub-embodiment of theprocesses disclosed herein, the heating occurs for no more than 10minutes at a temperature of at least 110° C. In other embodimentsaccording to the first sub-embodiment of the processes disclosed herein,the heating occurs for no more than 8 minutes at a temperature of atleast 125° C.

According to the second sub-embodiment, a method is provided forremoving organic solvents from wet guayule bagasse. The method comprisesproviding a quantity of wet guayule bagasse that contains up to 40weight % of acetone, hexane and water combined (based upon the totalweight of the wet guayule bagasse) and no more than 0.1 weight % rubber.The wet guayule bagasse is heated to a temperature of greater than 100°C. whereby the acetone and hexane are evaporated. After evaporation ofthe organic solvents, dried bagasse that contains no more than 1 weight% combined weight of acetone and hexane is produced.

As previously discussed, according to the second sub-embodiment, the wetguayule bagasse is heated to a temperature greater than 100° C. wherebythe organic solvents are evaporated. In certain embodiments according tothe second embodiment, the wet guayule bagasse is heated to atemperature between 110 and 200° C.

In certain embodiments according to the second sub-embodiment of theprocesses disclosed herein, the heating occurs for no more than 10minutes at a temperature of 100 to 200° C. In other embodimentsaccording to the second embodiment of the processes disclosed herein,the heating occurs for no more than 8 minutes at a temperature of 105 to130° C.

As previously discussed, according to the first embodiment and the firstand second sub-embodiments of the processes disclosed herein, the driedbagasse contains no more than 1 weight % organic solvent (based upon thetotal weight of the dried bagasse). In addition to the organic solventcontent of the dried bagasse, the dried bagasse may contain a quantityof water and higher boiling point terpenes. Generally, the totalquantity of water and higher boiling point terpenes in the dried bagassemay be higher than the content of organic solvents. The total quantityof water and higher boiling point terpenes may vary, although the amountof water is preferably minimized to no more than 10 weight % (based onthe total weight of the dried bagasse), even more preferably no morethan 5 weight %. In certain such embodiments of the processes disclosedherein, the dried bagasse contains no more than 0.5 weight % organicsolvent (based upon the total weight of the dried bagasse). In yet othersuch embodiments of the processes disclosed herein, the dried bagassecontains no more than 0.2 weight % organic solvent (based upon the totalweight of the dried bagasse).

As previously discussed, according to the second sub-embodiment of theprocesses disclosed herein, the wet guayule bagasse is heated to atemperature of greater than 100° C. whereby the acetone and hexane areevaporated. Various methods may be utilized for the heating of the wetguayule bagasse. In one embodiment of the second sub-embodiment of theprocesses disclosed herein, the heating is achieved by placing the wetguayule bagasse in an apparatus containing multiple layers, circulatingheated air through the layers of the apparatus and passing the wetguayule bagasse from one layer to another. Suitable equipment forachieving this type of heating includes continuous tray-type dryers suchas those available from Wyssmont Company (Fort Lee, N.J.). In otherembodiments of the second embodiment of the processes disclosed herein,the heating is achieved by the use of other apparatus, including thosediscussed above.

In certain embodiments according to the second sub-embodiment of theprocesses disclosed herein, the method of removing acetone and hexanefrom the wet guayule bagasse further comprises condensing the evaporatedorganic solvents and collecting them separately from the dried bagasse.

In certain embodiments according to the first embodiment and accordingto the first and second sub-embodiments of the processes disclosedherein, the dried bagasse is compressed by a compression machine to forma compressed material. In certain embodiments, the compressed materialis a briquette or pellet that has a density that is 150-325% higher thanthe density of the non-compressed chopped plant matter. In yet otherembodiments, the briquettes have a density that is 40-100% higher thanthe density of the non-compressed chopped plant matter. Briquettes withsuch densities can provide advantages in terms of being easier toproduce and easier to grind and dissolve in organic solvent. In certainembodiments, the briquettes have a density of 3 to 8.5 pounds/gallon(0.4 to 1 kg/liter). This density is the true density of the briquettes(excluding the volume of pores) and not a bulk density. Various methods(e.g., optical, gas expansion and liquid imbibitions) for determiningthe true density of a porous solid exist and are known to those skilledin the art, but they all generally entail measuring the volume of poresexisting within the porous solid so that this volume can be excludedfrom the volume that is used to calculate true density.

As used herein the terms briquette and pellet are used interchangeablyand should be construed broadly to encompass various forms or shapes,including, but not limited to, pellets, cubes, rectangular solids,spherical solids, egg-shaped solids, bricks and cakes. Various methodsexist for compacting the bagasse into briquettes. One method ofpreparing briquettes from the bagasse is to utilize a commercialbriquetting machine to prepare the briquettes. Various companiesmanufacture these machines and they are available in various sizes andspecifications. Exemplary briquetting machines include thosemanufactured by K.R. Komarek, Inc. (Wood Dale, Ill.), including theroll-type briquetting machines model no. B100R and BR200QC. Generally, abriquetting machine utilizes a roll-type system to compact material,with or without the addition of a binder to the material that is beingcompressed. Pressure can be applied by the machine in varying amountsdepending upon the machine utilized, the properties of the chipped plantmatter and the properties desired in the briquettes. In certainembodiments, of bagasse from guayule shrubs are made using a briquettingmachine. In certain of the foregoing embodiments, binder is applied tothe bagasse plant matter prior to its being compressed into briquettes.In certain of these embodiments, the binder comprises resin (e.g.,guayule resin) that has been extracted from the plant matter during therubber extraction process. Other methods of preparing briquettes ofbagasse from non-Hevea plants may be utilized within the scope of theprocesses and systems disclosed herein. In this regard, the disclosureof U.S. Patent Application Ser. No. 61/607,475 entitled “Processes ForRecovering Rubber From Non-Hevea Plants Using Briquettes” is hereinincorporated by reference.

EXAMPLES Example 1

Simulated wet bagasse was prepared by mixing 73.84 grams of hexane,18.44 grams of acetone and 228.48 grams of bagasse together. The bagassehad been obtained after organic solvent extraction and solvent rinsingof wet guayule pellets. Prior to organic solvent the wet guayule pelletswere found to contain 11.74 weight % moisture, 6.67 weight % rubber (dryweight basis) and 8.44 weight % resin (dry weight basis). Prior to usein the wet bagasse, the bagasse was analyzed and found to contain 8.19weight % moisture, 1.55 weight % rubber and 2.56 weight % resin. Thesimulated wet bagasse was placed in a preheated 64 ounce stainless steelbowl on a hot plate set at 125° C. The wet bagasse was agitated with amechanical mixer. Samples were taken at various drying times. Percentvolatiles were measured by thermogravimetric analysis. Weight %hexane+acetone was analyzed by head space gas chromatography. The dryingtime to a residual solvent level (i.e., hexane+acetone) of no more than0.5 weight % in the bagasse was found to be about 6 minutes. Results arereported in Table 1.

TABLE 1 Sample Drying Time % Hexanes + Number (Min) % Total VolatilesAcetone 1 0 24.477 7.882 2 1 25.016 8.304 3 2 8.429 1.048 4 3 14.2315.33 5 4 14.995 6.032 6 5 10.358 2.079 7 6 9.562 0.539 8 15 4.71 0.352 920 2.653 0.137 10 25 2.076 0.088 11 30 1.069 0.049 12 35 0.782 0.044 1340 1.036 0.046 14 45 2.141 0.081 15 50 1.077 0.043 16 55 0.896 0.039 1760 0.941 0.038 18 70 0.801 0.034 19 80 0.908 0.033 20 90 0.667 0.06 21100 0.608 0.024 22 110 0.577 0.023 23 120 0.404 0.02

Example 2

A quantity of solvent-wet bagasse was processed through a tray dryer inorder to remove the solvents and produce dry bagasse. The solvent-wetbagasse resulted from the following general process: guayule shrubmaterial was subjected to size reduction (chipping to reduce the shrubto 1-3″ size pieces), followed by hammer milling and then screened usinga 1″ screen), the size reduced guayule shrub material was subjected tosolvent extraction (using 80% hexane, 20% acetone) to remove most of therubber an resin from the guayule shrub material. The solvent-wet bagassewas fed into a stainless steel tray dryer. The dryer contained 16 dryingtrays and 4 cooling trays. The tray dryer was configured so as to allowheated air to circulate over the top and bottom of each tray. Thetemperature inside of the tray dryer was maintained at 70-85° C. and theatmosphere inside of the tray dryer was maintained at +25 to −10 inchesof H₂O. Bagasse was allowed to remain in the tray dryer forapproximately 1-1.5 hours. The solvent-wet bagasse entering the traydryer had a solvent content of about 40-75 weight % and the bagasseexiting the tray dryer had a solvent content of no more than about 1500ppm.

Example 3

A quantity of solvent-wet bagasse was processed through adesolventization screw extruder in order to remove the solvents andproduce dryer bagasse. Dried guayule bagasse obtained from a previoustrial was wet with solvent (hexane) to produce a composition containing70 weight % solvent and 30 weight % bagasse. The solvent-wet bagasse wasfed into the desolventization screw extruder. The screw extruder wasconfigured to allow input of the bagasse, followed by hexane feed. Twosolvent tanks were placed below the extruder to collect solvent, with a0.3 mm slit and seal configuration in the extruder above the firstsolvent tank and a 0.15 mm slit and seal configuration in the extruderabove the second solvent tank. The area of the extruder encompassing thesolvent tanks was considered the dewatering zone. Subsequent to thedewatering zone, was another a degasification vacuum over a 200 meshfilter followed by another vacuum after which the dryer bagasse was toexit the extruder via a die. The use of aggressive (i.e., thicker andtighter) seals was found to result in undesirable compacting of thebagasse material; changing to less aggressive seals allowed fordewatering to begin in solvent tank 1.

Various operating conditions were investigated as summarized in Table 2below. In later trials, because the amount of dry bagasse was limited,recycled bagasse (containing 10-20 weight % solvent) was reused bymixing with hexane to make a 30% solvent containing feed. Despite thelowering of the solvent content on the solvent-wet bagasse being fedinto the screw extruder, problems with clogging were still experiencedwith the degasification vacuum present near the end of the extruder suchthat in only one instance was it possible to draw a vaccum on the 200mesh filter.

TABLE 2 % Solvent solvent Screw tank in Sample Hexane Bagasse Screwspeed Slit size (kg/h) discharge # (kg/h) (kg/h) config. (rpm) 1st 2ndvacuum 1st 2nd bagasse 1 55 25 3 100 0.15 0.8 X X x X 2 77 77 4 200 0.30.15 X 45 X 43% 3 77 77 4 300 0.3 0.15 X 20 X 55% 4 77 77 4 150 0.3 0.15X 46 X 36% 5 77 77 4 100 0.3 0.15 X 55 X 30% 6 77 77 4 100 0.3 0.15 X 55X 27% 7 77 77 4 80 0.3 0.15 X 26% 8 130 77 4 150 0.3 0.15 X 29% 9 130 774 200 0.3 0.15 X 38% 10 130 77 4 100 0.3 0.15 X 26% 11 130 77 4 300 0.30.15 X Free liquid 12 31 77 5 120 X X X 18% 13 31 50 5 100 X X X 33% 1431 77 5 100 X X X 28% 15 Recycled Bagasse 10% 16 16 77 6 100 X X X 13%17 16 77 6 100 X X X 16% 18 77 100 x X Yes 20%

To the extent that the term “includes” or “including” is used in thespecification or the claims, it is intended to be inclusive in a mannersimilar to the term “comprising” as that term is interpreted whenemployed as a transitional word in a claim. Furthermore, to the extentthat the term “or” is employed (e.g., A or B) it is intended to mean “Aor B or both.” When the applicants intend to indicate “only A or B butnot both” then the term “only A or B but not both” will be employed.Thus, use of the term “or” herein is the inclusive, and not theexclusive use. See Bryan A. Garner, A Dictionary of Modern Legal Usage624 (2d. Ed. 1995). Also, to the extent that the terms “in” or “into”are used in the specification or the claims, it is intended toadditionally mean “on” or “onto.” Furthermore, to the extent the term“connect” is used in the specification or claims, it is intended to meannot only “directly connected to,” but also “indirectly connected to”such as connected through another component or components.

While the present application has been illustrated by the description ofembodiments thereof, and while the embodiments have been described inconsiderable detail, it is not the intention of the applicants torestrict or in any way limit the scope of the appended claims to suchdetail. Additional advantages and modifications will readily appear tothose skilled in the art. Therefore, the application, in its broaderaspects, is not limited to the specific details, the representativeapparatus, and illustrative examples shown and described. Accordingly,departures may be made from such details without departing from thespirit or scope of the applicant's general inventive concept.

What is claimed is: 1-16. (canceled)
 17. A method for removing organicsolvents from wet bagasse comprising: utilizing a quantity of wetbagasse that contains up to 45 weight % combined organic solvents andwater (based upon the total weight of the wet bagasse) and no more than0.1 weight % rubber; heating the wet bagasse to a temperature of atleast 100° C. whereby the organic solvents are evaporated; producingdried bagasse that contains no more than 1 weight % organic solvents.18. The method according to claim 17 where the bagasse is from guayuleshrub.
 19. The method according to claim 17, wherein the heating takesplace in an apparatus selected from the following: i. a dryer containingmultiple layers, circulating heated air through the layers of theapparatus and passing the wet guayule bagasse from one layer to anotherwhereby the organic solvents are evaporated; ii. a dryer containingmultiple paddles for mixing the wet bagasse with heated air to evaporatethe organic solvent; or iii. a desolventization screw extruder,producing dried guayule bagasse that contains no more than 1 weight %organic solvents.
 20. The method according to claim 17, wherein theheating occurs for no more than 10 minutes at a temperature of at least110° C.
 21. The method according to claim 17, wherein the dried bagassecontains no more than 0.5 weight % organic solvent.
 22. The methodaccording to claim 19, wherein the heating utilizes apparatus (i). 23.The method according to claim 22, wherein the heated air has atemperature of 100-150° C.
 24. The method according to claim 17, whereinthe wet bagasse remains in the apparatus for 5-90 minutes.
 25. Themethod according to claim 17, wherein the heating is achieved by heatedsteam.
 26. The method according to claim 17, further comprisingcondensing the evaporated organic solvents and collecting themseparately from the dried bagasse.
 27. The method according to claim 17,further comprising compressing the dried bagasse into a briquette havinga density that is at least 40% greater than the density of thenon-compressed dried bagasse.
 28. The method according to claim 17,wherein the combined solvents are acetone and hexane.
 29. The methodaccording to claim 23, wherein the dried bagasse contains no more than0.2 weight % organic solvent.
 30. A method for removing organic solventsfrom wet guayule bagasse comprising: utilizing a quantity of wet guayulebagasse that contains up to 45 weight % combined organic solvents andwater (based upon the total weight of the wet bagasse) and no more than0.1 weight % rubber; heating the wet guayule bagasse to a temperature ofat least 100° C. whereby the organic solvents are evaporated; producingdried guayule bagasse that contains no more than 1 weight % organicsolvents, wherein the heating takes place in an apparatus selected fromthe following: i. a dryer containing multiple layers, circulating heatedair through the layers of the apparatus and passing the wet guayulebagasse from one layer to another whereby the organic solvents areevaporated; ii. a dryer containing multiple paddles for mixing the wetguayule bagasse with heated air to evaporate the organic solvent; oriii. a desolventization screw extruder, producing dried guayule bagassethat contains no more than 1 weight % organic solvents.
 31. The methodaccording to claim 30, wherein the heating occurs for no more than 10minutes at a temperature of at least 110° C.
 32. The method according toclaim 30, wherein the dried guayule bagasse contains no more than 0.5weight % organic solvent.
 33. The method according to claim 30, furthercomprising condensing the evaporated organic solvents and collectingthem separately from the dried guayule bagasse.
 34. The method accordingto claim 30, further comprising compressing the dried guayule bagasseinto a briquette having a density that is at least 40% greater than thedensity of the non-compressed dried guayule bagasse.
 35. The methodaccording to claim 30, wherein the combined solvents are acetone andhexane.
 36. The method according to claim 32, wherein the combinedsolvents are acetone and hexane.